env-lock

A process's environment is a form of global mutable state. In Rust, tests are run in a shared process. This means tests that modify environment variables can inadvertently affect each other. env-lock provides an interface to safely modify and lock the process environment, to prevent simultaneous access.

use std::env;

let var = "ENV_LOCK_TEST_VARIABLE";
assert!(env::var(var).is_err());

let guard = env_lock::lock_env([(var, Some("hello!"))]);
assert_eq!(env::var(var).unwrap(), "hello!");
drop(guard);

assert!(env::var(var).is_err());

lib.rs:

Lock environment variables to prevent simultaneous access. Use [lock_env] to set values for whatever environment variables you intend to access in your test. This will return a guard that, when dropped, will revert the environment to its initial state. The guard uses a [Mutex] underneath to ensure that multiple tests within the same process can't access it at the same time.

use std::env;

let var = "ENV_LOCK_TEST_VARIABLE";
assert!(env::var(var).is_err());

let guard = env_lock::lock_env([(var, Some("hello!"))]);
assert_eq!(env::var(var).unwrap(), "hello!");
drop(guard);

assert!(env::var(var).is_err());